(i) Technical Field
The present invention relates to a compressor and a vacuum machine.
(ii) Related Art
There is known a compressor and a vacuum machine where a piston reciprocates within a cylinder by a motor. Japanese Patent Application Publication No. 2004-183498 discloses such a compressor. As for general compressor and vacuum machine, a cylinder body and a cylinder head are provided outside a crankcase.
In order to provide the cylinder body and the cylinder head outside the crankcase, the cylinder body is secured to a wall portion of the crankcase, and the cylinder head is secured to the cylinder body. In this case, a seating portion on which the piston is seated has to be provided separately from the wall portion of the crankcase. Therefore, the whole size of the device may increase in such a direction that the piston moves. Also, an exclusive part functioning as the seating portion is needed, so that the number of the parts increases.
On the other hand, in order to downsize the compressor and the vacuum machine, the cylinder or the crankcase is reduced in size. However, if the cylinder is reduced in size, absorption or discharging ability of the compressor and the vacuum machine might deteriorate. Also, if the crankcase is reduced in size, the cylinders interfere with each other. Thus, there is a limit in reducing the crankcase in size.